alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Hupigon.DF Checkin"; flow:to_server,established; urilen:7; http.uri; content:"/ip.txt"; http.user_agent; content:"Huai_Huai"; depth:9; endswith; reference:md5,ee600bdcc45989750dee846b5049f935; reference:md5,1051f7176fe0a50414649d369e752e98; classtype:command-and-control; sid:2018762; rev:5; metadata:created_at 2012_07_14, signature_severity Major, updated_at 2020_10_14;)